(i) Field of the Invention
The present invention relates to a head cleaner for removing foreign matters sticking to a magnetic head in a magnetic tape read/write apparatus having a rotary head.
(ii) Description of the Related Art
Since the entire surface of a magnetic tape is scanned to perform read/write with an extremely narrow (about 0.06 mm) magnetic head in the magnetic tape read/write apparatus provided with the rotary head, after repeated use, dust and other foreign matters having stuck to the magnetic tape stick to the magnetic head and are accumulated. In this case, since the foreign matters exist between the magnetic tape and the magnetic head, the magnetic tape adheres to the a magnetic head and cannot run, thereby deteriorating the read/write ability, and further frequently resulting in the generation of read errors. Serious problems are thus caused.
For a prior-art head cleaner, for example, in the structure disclosed in Japanese Patent Application Laid-Open No. 102112/1997, as shown in FIG. 3, a cleaning member containing an abrasive in a sponge-like member is used as a cleaning roller 13, the roller is rotatably supported by a roller shaft 15, and an arm 14, to which the roller shaft 15 is fixed, is moved, so that the roller 13 is allowed to abut on a rotary head drum 11, and performs cleaning, and is detached from the drum after the cleaning.
The operation of this prior art will next be described. When the cleaning roller 13, detached from the rotary head drum 11 and not rotating, is allowed to abut on the rotating rotary head drum 11, foreign matters are scraped off as long as there is a difference in peripheral velocity between the outer peripheries of the cleaning roller 13 and rotary head drum 11 immediately after the abutment. However, after the rotation of the cleaning roller 13 is started and the peripheral velocity is close to that of the rotary head drum 11, the cleaning roller 13 and the rotary head drum 11 contact each other just to roll. Since both components fail to rub each other, cleaning effect is disadvantageously eliminated.
As a first prior-art problem, in the system in which the cleaning roller rolls together with the rotary drum, unless the force of the cleaning member constituting the cleaning roller 13 for attracting the foreign matters is stronger than the adhesive force of the foreign matters sticking to the magnetic head and the magnetic head, the foreign matters fail to move to the cleaning member, and no cleaning effect can be expected. When the foreign matters have adhesive properties, they adhere to the head. Therefore, unless the adhesive force of the foreign matters with the cleaning member is stronger than the adhesive force with the magnetic head, the foreign matters cannot be removed even in a long time. A technique for allowing the cleaning member to contain an abrasive or a lubricating oil is also disclosed in the Japanese Patent Application Laid-Open No. 102112/1997, but there is also a problem that when highly adhesive substances adhere to the magnetic head, the substances cannot be removed.
A second problem is that a very small amount of lubricating oil is applied to the surface of the magnetic tape in order to reduce friction with the magnetic head and a tape guide for guiding the tape to the magnetic head or a capstan. Therefore, when the given amount of or more magnetic tapes are treated, the lubricating oil sticking to the rotary head drum moves to and is accumulated on the surface of the cleaning member constituting the cleaning roller 13, and the force of the cleaning member for attracting the foreign matters to itself is gradually weakened, thereby causing a problem that it becomes difficult to remove the foreign matters from the magnetic head.
The present invention has been developed to find out solution measures in consideration of the above-described prior-art problems.
An object of the present invention is to forcibly scrape off foreign matters by rotating a cleaning member by the drive power of a motor or the like and placing the cleaning member in contact with a magnetic head, fulfill an original read/write performance or characteristic, and to enhance reliability.
According to the present invention, there is provided a head cleaner for contacting/rotating the sliding surface of a rotary head drum for use in a magnetic tape read/write apparatus to perform cleaning, comprising:
a motor for operating by an external power independently of the rotation of the rotary head drum; and
a cleaning member for being forcibly driven by the motor to rotate.
The head cleaner of the present invention further comprises rotary cleaning member moving means for pressing or detaching the cleaning member to or from the rotary head drum.
The cleaning member of the head cleaner according to the present invention comprises a rotary brush including a plurality of bristles.
In the head cleaner of the present invention, the rotation shaft direction of the rotary brush is substantially parallel with a tangent line on the side face of the rotary head drum in a point in which the rotary head drum abuts on the rotary brush and the upper surface of the rotary head drum.
The rotary brush has a substantially cylindrical shape, the bristles of the rotary brush are extended in a radial manner on the line connecting the center of the rotary brush and the outside, and the bristles of the rotary brush rub the rotary head drum in parallel with the rotation shaft of the rotary head drum to perform a cleaning operation.
In the head cleaner of the present invention, the rotation shaft direction of the rotary brush substantially agrees with a normal direction in a point in which the rotary head drum abuts on the rotary brush.
The rotary brush has a substantially cylindrical shape, the bristles of the rotary brush are extended in parallel with the normal direction, and the bristles of the rotary brush may rub the rotary head drum to perform the cleaning operation.
The head cleaner of the present invention further comprises an arm having one end for supporting the motor and a middle portion rotatably supported on an apparatus base by an arm support pin,
a spring having one end connected to the other end side of the arm, and the other end connected to the apparatus base, and
a follower roller on the other end of the arm.
The follower roller is in a position relation in the magnetic tape read/write apparatus in which when a loading cam wheel for rotating with the load/unload operation of a magnetic tape is rotated and a cam on the side face of the loading cam wheel pushes up the follower roller, the follower roller moves apart from the center of the loading cam wheel.
The follower roller of the head cleaner according to the present invention is constituted of a shaft fixed to the other end of the arm, and a roller rotatably supported on the shaft.
The head cleaner of the present invention further comprises a micro switch positioned on the opposite side of the loading cam wheel as seen from the other end of the arm, and positioned to contact the arm only when the follower roller is pushed up by the cam.
When the micro switch contacts the arm, the micro switch turns on and the motor rotates and the rotary head drum slowly rotates, and when the micro switch is detached from the arm, the micro switch turns off and the rotation of the motor stops.
In this constitution, since the rotary cleaning member can rotate itself, the rotary cleaning member scrapes off or rubs off foreign matters, so that the foreign matters can be removed. Therefore, the removing performance is largely enhanced as compared with the prior art which depends only on the adsorptive force of the cleaning member. Moreover, the shaft of the rotary head drum and the rotation shaft of the rotary cleaning member can be set to be parallel with each other, be at right angles to each other, or to form any other arbitrary angle with each other. Therefore, even unless the rotary head drum shaft is driven, rotation is applied to the outer periphery of the rotary head drum by the rotation of the rotary cleaning member so that the foreign matter removing operation can be performed.